Dashboard layout changes

Upgrade jquery to 1.9.1 and add jquery migrate plugin for compatibility.
Add jquery shapeshift plugin for layout.
Add jquery-ui and jquery.touch-punch - dependencies for shapeshift.
Add new js files in base.html
Add flot.js library to be used for graphs
Modify widget styles and dashboard configuration icon in style.css
Add RockStorWidget base class in rockstor.js
Modify cpuusage, sysinfo, and sample widget views to extend from
RockStorWidget base class
Add rezize and close icons and html changes for cpuusage, sysinfo and
sample widget
Modify renderWidget in home.js to use the shapeshift plugin for layout.
Dashboard layout - available widgets

Create new js object for list of available widgets in
rockstor_widgets.js
Classify widgets into Compute, Storage and Network categories.
Modify dashboard config view and template to display widgets from the
new list, and save changes.
Modify home.js to set default widgets in dashboard configuration, if
there is not dashboard configuration for the user.
Stacked bars for CPU graph

Add jquery.flotcharts stack plugins
Modify cpuusage view render functions to modify data into the required
format for flot, and use flot to render the graphs.
Corrected x axis tick rendering function and range
Dashboard layout default height and width and configuration saving

Add default height and width for widgets in rockstor_widgets.js
Modify renderWidgets to check for saved dashboard confg or read from
default config
Modify resize function to restore to original size.
Add saveWidgetConfiguration in home.js to save the current dashboard
state.
dashboard layout configuration

Add helper methods in DashboardConfig model to set and get
configuration.
In home.js, set dashboardconfig to default if it is empty.
Dashboard configuration - add and remove widgets

In dashboard_config template, get selected status from current dashboard
configuration
In the DashboardConfig view, use containers addWidget and removeWidget
methods to add and remove selections. Destroy shapeshift before and then
call shapeshift after widgets have been added/removed, so that new
widgets are initialized properly. (Triggering rearrange after a new li
has been added has issues see
https://github.com/McPants/jquery.shapeshift/issues/34)
Delegate saving the configuration to parent view method.
In the Home view, remove unnecessary handlers, and add removeWidget
method.
CPU widget resize handling

Add jquery.flot.resize plugin to handle resizing of graphs.
Remove row-fluid and span12 for the graph section of cpuusage template,
because the graph container is not able to figure out its height from
percentage values if they are present.
Set percentage heights and width on widget-content div, and the cpu
graph placeholder div, so that the resize plugin can automatically
resize acc to percentage value.
Move widget default configuration sections into individual widget views

Remove the widget configuration sections from rockstor_widgets.js
Add configurations for each widget in the widget js view file.
Modify widget templates to show displayName in the title
Add position for configurations so default widgets can be ordered.
Merge pull request #62 from sujeetsr/issue#51_dashboard_layout

Dashboard layout modifications